Go further, Economist. WHY are we getting so fat, especially children? List the top five reasons, with no taboos. Then take a look at how many corporations' profits are directly or indirectly impacted by those trends. Come on! Let's have some real analysis!

Its because 'big US corporate food' has made food cheap by filling it with cheap crap. Like high fructose corn syrup, which tricks the body into thinking its not taken in all those calories, and which through agricultural subsidies the US government is complicit in pushing onto its obese citizens. And because the US mentality of quantity over quality combines with the concept of individual choice and liberty to produce an ugly state of mind where shoving vast quantities of cheap crap down ones gullet is seen as being normal or good.

The truly terrible thing for the world is that US food companies continue to expand their supply chains globally. Coke, KFC, McDonalds, Kraft, Hershey's etc are all providing flavored fat, sugar and HFCS food analogues across the world. Its hard to escape. Look at the label. If its made by an American company, don't eat it. Buy something locally produced and fresh instead.

Dietary guidelines and the supporting official government approved “science” have been corrupt by special interests. Half a century ago when the USDA began developing dietary guidelines (the food pyramid etc.) most of the recommendations were the result of lobbying and corrupt “cigarette science” paid for by big corporate special interests. “Eat more grains, don’t eat eggs, margarine is better than butter, saturated fats is bad for you, trans fats is harmless, MSG is harmless, Aspartame is harmless etc.” None of these recommendations are actually supported by science.
If politicians really wanted to battle obesity they should take a fresh look at the scientific evidence and stop listening to the status quo defending scientists/bureaucrats/lobbyists that have whispered in their ears for decades.
Here is the answer:
*The big problem is carbohydrates and sugars, not fats and proteins. By changing the diet into a low carb high fat diet (LCHF) people would naturally feel satiated on fewer calories and eat less without any additional intervention. Taxing fats and not sugars/carbs is exactly the wrong way to go. High Fructose Corn Syrup is even worse than sugar and wreaks havoc on the body. But an aggressive industry lobby has managed to hijack the food regulators (FDA and EFSA) and keep the politicians in the dark about the risks from HFCS.
*Another problem is the depletion of industrial food of trace minerals, vitamins and various micro nutritional substances. People who are mineral deficient (chromium, magnesium, iodine, molybdenum, sulfur, zinc, selenium, copper, manganese, boron, etc.) will overeat in an attempt to replenish the missing minerals. Organic food and mineral supplementation can reduce this problem. Poor people who seldom eat real quality food are more exposed to this problem.
*But the real driver of the obesity epidemic is junk food additives that increase food craving and suppress the natural feeling of satiety. MSG (glutamate) in high doses has exactly that effect on the body. All artificial sweeteners (Aspartame, Sucralose, etc) have the same effect. Gelatin, yeast extract, and hydrolyzed proteins also have a similar effect. This fact is highly controversial and there is massive alleged “scientific” industry lobbing devoted to undermining and distorting the scientific credibility of these facts. Wonder why? Perhaps they want to sell more products?
The easiest way to curb the global obesity epidemic would be to ban MSG, Aspartame and HFCS and ensure that Big Food doesn’t circumvent these bans by introducing similar molecules. But Big Food is a powerful lobby that plays dirty. Corrupt and bribed politicians would most likely not make these simple decisions even though they would dramatically improve human health, increase the productivity of the work force, and reduce costs for care of the elderly and health care costs significantly.

3) have faith in human intelligence. As educated people enjoy falling incidence of obesity, and as society becomes more educated, obesity will stabilise and eventually decline as with smoking before it.

There are many reasons for the epidemic, but they all boil down to one thing: vested interests. The food industries want to continue selling excessive quantities of addictive food. The weight-loss industry wants continuing customers, not once-off customers. Pharmaceutical companies are salivating over the possibility of a drug that could let you eat sugary junk food and polyunsaturated vegetable oils and still remain slim. And the medical industry's lobby groups will do all they can in bribing the FDA and other bodies with false messages that keep their fat patients rolling in.
Obesity is an information war with poorer and more gullible people on the losing side. Sugar is highly addictive, and the root cause of insulin overload: see the site growyouthful dot com.
Polyunsaturated vegetable oils are the ones that make you sick and fat, NOT saturated animal fats. There's plenty of quality scientific research to prove it, and an ongoing information war funded by big business money against researchers with ethics.

I would guarantee you if you went on a strict ALL BUTTER diet and drank melted butter and ate three slices of lard as a lard-on-lard sandwich you would LOSE WEIGHT. You would also feel lethargic, listless, depressed and low energy--but you would also be thinner.

OR you could eat an All-Chocolate diet: 3 lbs of high fat milk chocolate... and lose weight. You predictably will feel lousy and lethargic, but will be markedly svelte.

The human body is optimized for a omnivorous diet including carbohydrates, vegetables, meat and dairy. Depriving the body of whole food groups like carbs, proteins, or fats causes the gastrointestinal system to operate outside of its ideal conditions.

You go into ketosis or alanine cycle metabolism.
And we lose equilibrium.
And you feel lousy and lethargic.
And a side effect is weight loss--Yeah!

It is like an engine miss-firing on a cylinder. It is suboptimal and underperforming. And you use more fuel just to keep up with traffic, but still look skinny.

But it is losing weight through unhealthful means. No different than weight loss after getting cancer.

And it will not be sustained.

The body will rebound to back to original weight like a yo-yo.

Natural homeostasis brings you back to your fat healthy self as soon as your diet ends. And it will end.

The reason why there are 1000 diets and diet books is that NONE WORK.
All are effective short term. But none provide a long lasting solution.
And the dieter is likely to go on and off, and on and off, of up to 50 diets over a lifetime.
And you need to build new bookshelves for all those diet books--perhaps your new exercise?

And weight fluctuates like a yo-yo.

The solution is not a special diet.

It is a lifelong habit of eating less calories and exercising--everyday.
It is as simple (or hard) as changing your lifestyle permanently.
Become more active. Eat a varied diet. But never eat too much.

You don't need a new diet...You need a new lifestyle.

Instead of the Miami Beach diet, join the Marines. One of these is an effective weight loss program--I will let your guess which one.

OR just change your own life by ditching the TV, walking to work, or adopting a puppy.

And if you want to get rich, write a diet book. Call it the 'Bacon Diet'. You will lose weight--at least in the short term.

We cannot blame Sugar or Fat; rather it is the excess of fat or sugar or protein or salt. Overeating tofu or granola will also cause sickness.

And just as important, absence of exercise and physical activity.

THE BEST PRESCRIPTION FOR WEIGHT LOSS:
EAT LESS AND EXERCISE MORE.
EAT MORE FRUIT AND VEGETABLES.
EVERYTHING IN MODERATION.
AVOID DIETS, DIETBOOKS AND CELEBRITY DIET ADVICE: They are Food Fads.

Please, do an article on several possible underlying causes of the epidemic of obesity in the world. This would include such issues as the use of antibiotics to help cows gain weight, bacterial balance in the gut as seen in fat mice and skinny mice (U. of Washington in St. Louis), bacterial gut balance in normal versus obese humans, changes in the type of wheat we eat today (see "Wheat Belly"), use of high fructose corn syrup rather than cane sugar, fluoridation of water altering thyroid function, low iodine levels in food today lowering thyroid function, possible infectious, inflammatory diseases causing diabetes, high blood pressure, inflamed arteries and then obesity in that order, antibiotic resistant chronic infections which may be causing these inflammations. And then perhaps look at new emerging diseases such as chronic fatigue syndrome, fibromyalgia, massive increases in lupus, ALS, ALZ and others. If you can do some reading and summarizing of the newer research on underlying causes of obesity you may find it isn't hamburgers and french fries. It isn't kid's computer toys either. Normal, healthy kids will not sit still for hours a day. They will get out and run and jump and hit a ball. What is wrong with the underlying health of children today? It isn't milk shakes.

The solution to obesity is simple: encourage smoking. Smokers tend to be skinny and die rapidly from cancer around age 65 so they don't withdraw from pension schemes. Plus, smoking supports domestic industry as most quality cigarettes are made in America.

I am wary of governments doing too much with food policy, because of their track record: A key reason reason why obesity has increased dramatically since 1980 is because that's when governments started telling people that dietary fat was bad. Unfortunately, the food industry responded to the government's advice by producing "low fat" food. To make low fat food satisfactory, the food industry relied on sugar and processed carbohydrates.

That's not to say that saturated fat is completely harmless. It's just that in hindsight, we can see that a high sugar/carb diet is actually far worse than a high fat diet.

Oh, and Ryvita and Orange juice? That's a perfect example of misguided advice. Separating the juice from the pulp of an orange concentrates the sugar, increases the quantity consumed, and increases its glycaemic index. The body then stores the excess calories as fat. Best eat oranges as they grew - whole.

MyopicTailor111 you are wright on!!! It is an OUTRAGE that Economist can print such garbage as this article and not address the food industry and the fact that most of stuff has all the additives and HFCS, it is negligence and perpetuating of misinformation!!! How the hell is this possible??? To put the blame on individual in face of all the evidence pointing to this manufactured artificial stuff that passes as food??? Outrageous!!! I feel disgusted in this moment that I am subscribing to this yellow paper!!!!! Unbelievable!!!!

People eat because they are fidgety. Its quite simple. Nobody is eating cookies while busy working on an excel sheet, or playing the guitar. Nobody is drinking pepsi while playing tennis or pitching a presentation.
One clue might lie in how our entertainment options have changed - the most interesting thing to do is to watch tv, which involves not moving or even thinking. This causes us to get fidgety..and we eat cause we are fidgety from just sitting in one place, our brain and body is now craving something else to do and the easiest thing is to put it to work processing food. once its done processing food, it now slows down everything for a little while...
Another example is automatic transmission - have you tried eating a cheeseburger and drinking pepsi while driving a manual transmission? Driving has transformed from an active pastime to a passive one - but not fully passive, meaning, just like when we watch tv..we are forced to sit in one place and stare at the window/tv meaning the rest of our body/mind is now fidgety again.
Obese ppl will tell you how hard it is to stop eating, its absolutely hell for them. Their brain is throwing every single fit and hurdle against it, and it takes massive willpower to get over it. On the flipside, an active person will tell you how easy it is to eat healthy all the time - if anything, their brains go into attack mode when they approach a cheeseburger. Truth is, even a little bit of exercise will make a huge difference in how the brain reacts to food. And THIS is exactly what we need to be concentrating on - helping people appreciate exercise, making it more accessible, Gyms cater only to fit people as much as clubs are for rich people - nobody wants to feel out of place. Lets make gyms a happy place for everyone.
Lets put a treadmill in every house. Lets play some tennis. Lets make an active lifestyle fun again.

In addition to what Concur said also remember that in the past the poor were often manual laborers while the rich sat around all day. Now the poor sit around all day at desks and have less leisure time to work out. Plus the rich usually have enough money to pay someone to nag them to work out.

The anti-smoking campaign is more informative than the pro-seat belt movement in my opinion. Seat belt wearing does not involve as many variables and I think the techniques are not as generalizable.
The secret sauce of the anti-smoking campaign was in giving people permission to look down on smokers, socially sanctioned derision. Certainly education has been important, especially for educated members of society. But it is the encouragement to openly disparage smokers and to shun them that has made anti-smoking campaigns so successful for adults. I think this and taxing cigarettes beyond the reach of children are the pillars of the movement.
Before we open the floodgates of haughty judgment against fat people, which will inevitably spill over into anti-poor, anti-minority and prejudice against the mentally retarded and many children, we need to come to a consensus in society that we are ready for such a movement. It would seem sporting to firm up the message about why fatness is bad and how much it is costing the nation. The word is slowly leaking out amongst the better educated but there has not been as much effort as was expended to vanquish smoking. We should give a wide scale education effort a chance, after that, in with the fatty jokes and openly prejudicial comments, starting at an early age.

Yes we can blame sugar (and other carbohyrates). Only carbohydrates provoke an insulin response and insulin regulates fat tissue, specifically it facilitates the storage of dietary fat and carbohyrate as body fat. Stop eating carbohydrates and you reduce or elinate the insulin response, then you cannot store fat. That is why the Atkins works.
More broadly, humans are not evolved to eat refined carbohydrates in large quantities. The logic of selection suggests we have not adapted to this recent phenomenon in our diet hence they make us fat and lead to other "diseases of civilisation".